What significant evolutionary trait is associated with Homo habilis?

The significant evolutionary trait associated with Homo habilis is the increased brain size. This early human species, which lived approximately 2.4 to 1.4 million years ago, is often considered a pivotal point in human evolution. The larger brain relative to body size indicates a transition towards more complex cognitive abilities, including problem-solving and social interaction. This increase in brain capacity is thought to have provided advantages that facilitated survival and adaptation in various environments.

While Homo habilis did show advancements in tool usage and is known for the development of Oldowan tools, the very essence of its classification as a key species in human evolution stems from the notable increase in brain size, which set the stage for further cognitive developments seen in later hominins. The traits of reduced tooth size and the development of complex language are more associated with later species in the Homo lineage. Thus, increased brain size is a defining characteristic that marks the evolutionary significance of Homo habilis.